1. Field of the Invention
This invention relates to an adjustable handlebar for a bicycle, whose handlebar members are pivotally movable about their adjacent ends and securely fixed and more particularly to an adjustable handlebar for a bicycle having handlebar grips whose inclined angles are adjustable.
2. Description of the Prior Art
There have been suggested many adjustable handlebars for bicycles, whose handlebar grips are vertically adjustable. For example, Japanese Utility Model Application Publication No. 18,728/72 discloses a handlebar, wherein after a lock nut and a clamp nut have been loosened, a right and a left handlebar member are separately pivotally moved into desired positions and after their symmetry has been ascertained, the clamp nut and lock nut are again tightened. Japanese Patent Application Publication No. 25,544/73 discloses a handlebar capable of adjusting heights of handlebar grips simultaneously. In adjusting the handlebar disclosed in this publication, it is however required to remove and again assemble four nuts, three washers, a jaw washer and a jaw washer support assembly consisting of a washer, a pivot shaft, a spring and an operating lever. These handlebars disclosed in these publications are complicated in construction and troublesome to handle and tend in use to cause loosening of the handlebars unacceptable for bicycle riding unless various screw-threaded members are fixedly tightened. Therefore, these handlebars have not been practically used yet.
In general, ideal positions and angles of handlebar grips of bicycles are different depending upon uses of the bicycles. For example, when a cyclist is riding a bicycle at a high speed as for sports, the upper half of his body is forwardly inclined as shown in solid lines A in FIG. 1. It is preferable to arrange grips of a handlebar in a lowered and forwardly shifted position B whose angle of elevation is small or near a horizontal as shown in a dot-and-dash line C. On the other hand, he assumes a comfortable position D shown in two dots-and-dash lines with the upper part of his body being upright when riding at usual or lower speeds. It is preferable in this case to arrange the grips in a raised position B' retracted by E, whose angle of elevation is comparatively large to reduce loads acting upon his wrists.
A handlebar for a bicycle fulfils such requirements has been expected in this technical field for long years.